Circulating-fuel system for oil engines



Q. L. GUMMEN$ CIRCULATING FUEL SYSTEM FOR OIL ENGINES Filed Sept.- 27

- INVENTOR,

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ticles to he vaporized within rimmed Oct. 13, 1925.

UNITED sTATes PATENT, orrice.

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Application filed September 27, 1921. serial Ito. 503,679.

To all whom it may concern:

Be it-known that'l, Cnnssrn L. CUM INS, a citizen of the United States and a resident of Columbus, county of fiartholomew,

and State of Indiana, have invented a fcer-v tain new and useful Circulating Fuel System for Oil Engines; and l do hereby declare that the following is a full, clear, and

exact description thereof, reference being had to the accompan ing drawings, in which like numerals reier to like parts.

' This invention relates to anoilengine for burning heavy fuel of the type wherein the fuel is burned by the heat of the air co n-. pressed by the piston within the combustion" pure chamber. With this type of engine air is drawn into the cylinder and heated therein by compression to a very high degree, the hot air entering a fuel cup through a small port thereinl At the same time this heat is transmitted through the holes and walls of the fuel cup, vaporizing part oi the fuel oil. which is discharged therein, so that this vapor ignites toy reason of the high degree ofhheat and explodes within the duel cup. 1 e force of such explosion inside of the cup separates the remaining fuel liquid into tiny particles, driving it out in a fine spray into the combustion chamber. This highly atomized fuel encounters the incandescent heat created in the cylinder, ignites and completely. burns. lhis causes the air in the cylinder to expandinanyrtim s its normal volume under-compress on, driving the piston on its power stroke.

Heretofore in oil engines of this type the heavy oil enters the fuel cup by gravity, passing through a port in the injector head and is controlled in volume hya valve tor that purpose. Diiiiculty has been experienced with this construction wherein the crude oil used in the engines contains a high percentage of gasoline, such as is found in the oil holds. it is, therefore, the purpose of this invention to so construct the injector and evolve a principle of fuel supply therein, as will cause the engine to he operated not only by kerosene or a 'fuel with a low percentage of gasoline, but also any fuel regardless of the percentage of gasoline which it may contain.

W here fuel oil is employed having a high percentage of gasoline, the extreme heat of the engine causes the gasoline parhe tuel inlet supply, To overcome it "a relatively cool condition.

and before reaching the fuel cup. Gas is given off by reason of such va orization and forms a gas pocket aroun the fuelv valve and inlet, the passa eway there thereby choking the 'en vention contemplates culation through the injector head and fuel valve so as to carry away all foreign inatter,d1rt and any gas formed in the fuel valve or passageway and maintain a' clear passage for the liquid fuel to enter the tueli form, stopping the flow of fuel to the cup,

arrangement whereby the fuel will hemaintained in cir-- cup.. Such circulation of the fuel through the in 'eetor also aids in eliminatin carbon :trom eing deposited by reason ot the in tense heat about the tuel and air valve therein, as the constant passa e of fuel therethrough carries 0a a portion of the heat and" tends to maintain such valves in.

The run nature oi the invention will he claims.

in the drawings, Fig. 1 is a side elevation oi the stationary type of oil engine embodying this invention. Fig. 2 is a plan view looking downupon the fuel injector and plug. Fig. 8 is a section taken on the line 3-5-3fof Fig. 2 showing a vertical section through the injector plug. Fig. i is a per spectiveflview of the in ector plug wit a uarter section cut therefrom illustrating l he fuel circulating passageway.

lln the drawings there is shown an oil engine supported by the base it) in which is contained a fuel reservoir 11. The base it) supports a cylinder 12 upon which is mounted a water hopper 13 for providing a water cooling medium to the cylinder. Supported upon the base it), there is a hearing it in which is mounted a crank shalt 15 having a tly wheel 16 secured tonne end thereof and a connecting rod 11? pivoted to said cranli: shalt at one end and to the reunderstood from the accompanying drawings and the following description and m1 plii ciprocating piston at the other end. This construction is of the usual type commonly found in the stationary oil engines.

The fuel is delivered to the fuel injector plug through the'auxi'liary fuel tank 18 into which fuel is pumped by the reciprocating flange 19 through the pump 20 and the fuel pipe 21. There is provided an overflow pipe 22 extending into the fuel tank 18 near the 10 top thereof so as to cause an excessive amount of fuel umped therein to flow-back into the main uel-reservoir 11. The fuel flowsby gravity from the tank 18 through the fuel line 23 to the fuel'injector, plug farm 27 which is pivoted at 28 on the cylinder "head and actuates the main air intake valve 29through the valve stem 30. Mounted be hind the push rod 26 and rocker arm 27 there is a similar rocker armand connecting rod for actuating an exhaust valve 1n the usual manner.

Mounted in the cylinder 31 there is a fuel injectorplug 32 which extends downwardly therein and carries a fuel cup 33 on the lower end thereof and the air and fuel valves for controlling the fuel supply to said,fuel cup. The uel cup 33 incloses a fuel chamber 34 which communicates with:

the passage 35 leading to the combustion chamber 36 of the engine through the open.- ings 37 of ,Which there are usually two or three. Forcontrollin'g and timing the injection of the fuel into the chamber 34, there isi-provided a valve. 38 mounted on the valve stem 39 which ismaintained in normall mounte uponsaid valve stem. 'The valve stem extends through an air chamber 41' in said plug and communicates with the atmosphere throughla small passageway 42 so as to 'permita small amount of air to enter the fuel chamber with the fuel. Extending at an angle to the valve. stem 39, there is a fuel inlet passage 43 which communicates with the fuel line 23, so that the liquid fuel passes down said passageway and communicates with the fuel chamber 44. Mounted in the fuel chamber 44, there is a needle valve 45 adapted to seat in a restricted opening communicating with the fuel chamber 34 through the valve 38. The needle valve 45' is positioned on the end of a valve stem 46 which extends upwardly through the injector plug into an inclosing head 47. The lower end of the valve stem 46 is surrounded closed position by the spring 40 gamma by a Spring 48 which normally maintains said needle valve in closed position, and is of such diameteras will leave an appreciable space for the passage of fuel within the fuel chamber 44. The upper part of the valve stem is hollow to provide a fuel passage 49 which communicates with the chamber 44 throughthe passageways 50, said upper portion containing within the passage 49 an;

actuating pin 51 adapted to be engaged by the valve controlling lever 52. The head 47 incloses a fuel chamber 53 into which the fuel enters from the chamber 44througl1 the passages 49 and 50. The chamber 53 com-' tion which may be created within the fuel passageways by the passage of the fuel to the reservoir.

Pivoted on the injector plug there is a lever 55 arranged to engage the valve stem 39 for actuating the fuel injection valve 38 at timed intervals, said lever being operated through the connecting rod 56 which is pivoted at one end to the rocker arm 27 and at the other end to the lever 57, said levers 55 and 57 being connected through the bearing portion 58 of said plug. This causes the valve38 to open at timed intervals for admitting a new charge of fuel into the fuel cup 34. The amount of the fuel charged and admitted by said valve is controlled by the needle valve which is controlled through the lever 52 by the speed control hand wheel 59,, or automatically by the governor 60 operatingthrough the connecting rods 61 and 62, the rods 62 being connected to the lever 52 through the arm 63.

In operation the fuel is first poured into the, reservoir through the main filler pipe 64, and upon cranking the engine, it is pumped into the auxiliary tank 18 where it descends by gravity through the fuel line 23 and fuel passage 43 into the fuel chainber 44. The needle valve 45, being adjusted by the control wheel 59, admits a certain charge of fuel into the chamber 65, said charge being in position to be admitted to the fuel chamber 34 when the valve 38 is actuated at the proper time. The air drawn by the suction of the engine into the chamber 41 is then admitted with the charge of fuel when the valve 38 opens. This mixture of fuel and air then descends to the fuel chamber 34 where it is heated to such a degree by the compressed air in the com-- bustion chamber that the more volatile parts of the fuel will be caused to ignite. The ignition of the vapor in said chamber causes a small premature explosion which drives the heavier fuel out through the opening 37 in a substantially atomized condition, passing through the passageway 35 into the combustion chamber where the incandescent heat causes the burning thereof and the consequent expansion of the air for causing the power stroke of the piston. The

above operation of the engine is common to this type and is well known in the art. However, in using heavy fuels containing an appreciable percentage of gasoline, the intense heat about the valves 38 and 45 causes a gas to be formed within the fuel chamber 44 which lies around-the needle valve and prevents the fuel, from freely flowing therethrough, by gravity with the consequent choking of the, engine for lack of fuel. To drive away this gas and keep it from forming at that point a system of circulation of the fuel is provided. By means of this arrangement the fuel entering through the fuel line 23 passes by gravity through the fuel passage 43 into the chamber 44. Because of the high elevation of the auxiliary tank 18, or where no auxiliary tank is used and the fuel is pumped. directly into the injector head, such fuel as is not admitted through the needle valve 45 will pass up through the chamber 44, passageways 50 and 49 into the chamber 53 and out through the, overflow pipe 24 and pipe 22 back to the reservoir. A continuous circulating current of fuel will, therefore,

be set up through the fuel chamber 44 so as,

to carry away any gas which may be formed therein about the valve 45. Such circulation of fuel will also carry away an appreciable amount of the heat generated about said valve so as to maintain it in relatively cooled condition, and thereby reduce the amount of carbonization which would'other- Wise be formed about said chamber and valve is mounted, a control device for the valve, an enclosure for the control device, a source of fuel, and circuating means forcing fuel to said valve an including an inlet communicating with said passage and an outlet from the enclosure to said fuel source to permit the excess fuel to return to said source.

2. In an oil engine, the combination of a combustion space, a vaporizing chamber, a valve for admitting liquid fuel to said chamber having a recess in its upper'end, a spring coiled about a reduced portion of said valve, a passageway in which said valve is mounted, a control device for the valve, a closed compartment for said control device, a main fuel tank and an auxiliary fuel tanlr disposed above the main fuel tank, means for forcing fuelinto said chamber from said auxiliary fuel tank, and means for passing unused fuel from said chamber to said main fuel tank comprising an outlet in said closed compartment and a passageway from said outlet to said main fuel tank whereby circulation of oil is maintained around said fuel valve.

In witness whereof, I have hereunto afiixed my signature.

CLESSIE L. CUMMINS. 

